I live on our family farm where I have a lot and have built a house. I have my animals on the other portion of the farm that she owns. It's very complicated how the farm is split up. She would never give my sister and myself our inheritance before she passes, because she think we would never go see her. Which is probably true because she's awful! I've tried distancing myself, trying to not let her get me upset. That just came back to bite me too. My sister keeps saying that I just need to listen and not get upset. No matter what I do it just feeds the fire. She's always been worse to me than my sister. I'm 57 years old and just want to throw my hands up, sell my house, change my phone number and forget her. I don't want to sell my house because I've lived there 35 years. I've worked hard for what I have. I just can't take it any more.
I assume that there may be another 10 or 15 or more years this woman will be in your life. She isn't going to change. It would make sense to learn all you can about dealing will people who have this particular mental illness. Maybe it is a matter of not letting her upset you, as your sister advises. Maybe it throwing up your hands and selling the house. Maybe there is a better solution.
There are regulars on the forum who have/are dealing with a narcissistic parent. They can speak from experience.
Sorry to hear how you are feeling. Its so hard being the daughter that stays and tries to help an elderly parent. I know its not easy. Have you considered consulting with a lawyer about your rights? Maybe talking to a social worker, therapist or counselor might help work out some of the issues with your mother or help give you tools in talking with her. My mother also makes me crazy. I feel the same way sometimes. For me, distance does help. She is still young only her in her 60s, but she has agreed to go to assisted living or a nursing home when the time comes. Thinking of you.